1. Field of the Invention
This invention relates to a hard disk device, which is a magnetic memory device for personal computers, word processors and so forth, and more particularly to a magnetic head for such a hard disk device.
2. Related Art
A variety of magnetic heads different in structure and in configuration have been proposed for hard disk devices, which are magnetic memory means for such electronic devices as those mentioned above, depending on the purposes of use and the functions required. FIGS. 5(a) and (b) show a monolithic type magnetic head 1 for a hard disk device. More specifically, FIG. 5(a) is a perspective view of the magnetic head 1, and FIG. 5(b) is a sectional view showing essential components of a leading core and a trailing core in the magnetic head 1.
The conventional monolithic type magnetic head 1, as shown in FIGS. 5(a) and (b), comprises: the trailing core 2, and the leading core 3 serving as a slider. The trailing core 2 and the leading core 3 are both made of a magnetic substance such as ferrite. Magnetic metal films 4 and 5 are formed on the junction surfaces of the trailing core 2 and the leading core 3, respectively, which are the magnetic path forming regions thereof. The trailing core 2 has a winding.
FIG. 6(a) and (b) show a conventional composite type magnetic head 10 for a hard disk device. More specifically, FIG. 6(a) is a perspective view of the magnetic head 10, and FIG. 6(b) is a sectional view showing essential components of a head core 11 which forms a magnetic circuit in the magnetic head 10.
The conventional composite type magnetic head 10, as shown in FIG. 6, comprises: the aforementioned head core 11 made of a magnetic substance such as ferrite; and a slider 12 made of a non-magnetic substance such as ceramic. The head core 11 is made up of a trailing core 13 and a leading core 14, which have magnetic metal films 15 and 16 on their junction surfaces, respectively.
In the conventional hard disk magnetic heads 1 and 10 designed as described above, the magnetic circuits of the trailing cores and the leading cores are formed by the ferrite and the magnetic metal films 4 and 5, and 15 and 16 formed on the ferrite.
Hence, in each of the trailing cores of the magnetic heads 1 and 10 which have the windings, the ratio of inductance to output is liable to be high, so that it is difficult to improve the high frequency characteristic thereof. In addition, because of the high ratio of inductance to output, it is impossible to use a head amplifier which is extensively employed for a thin film head. This makes it difficult to reduce the manufacturing cost of the hard disk device.
Furthermore, the transition of a magnetic domain wall due to the formation of a magnetic domain wall of ferrite near the air bearing surfaces of the leading core and the trailing core is not smooth, thus resulting in the occurrence of "wiggle".